Vehicle-to-X communication systems which are designed for transmitting traffic-related data and various service data items such as, for example, entertainment applications, are already known in the prior art. Vehicle-to-X communication is based here both on the exchange of data between vehicles (vehicle-to-vehicle communication) and the exchange of data between vehicles and infrastructure devices (vehicle-to-infrastructure communication). In order to avoid overloading the limited number of communication channels available for the transmission of data, the transmitted vehicle-to-messages are often at least partially compressed. Compatibilization of the data format of the vehicle-to-messages is also known in the prior art in order to enable two-way communication between vehicle-to-X communication systems of different types. Owing to the stringent requirements regarding the reliability and data security of information transmitted by means of vehicle-to-X communication, information of this type is often additionally provided with a complex security signature.
DE 10 2008 060 231 A1 describes in this context a method for selecting different data transmitted by means of vehicle-to-X communication. On the basis of a data frame, the received data is differentiated by a data filter in the receiver device and passed on, for example, to a driver assistance system or an entertainment device. This permits the received data to be sorted before its actual processing. For the transmission of the data, transmitter and receiver devices based on the WLAN Standards 802.11a/b/g/n at 2.4 GHz or the WLAN Standard 802.11p at 5.9 GHz are used. In order to transmit the data redundantly and to increase the reliability of the transmission, simultaneous transmission on both WLAN frequencies is also possible.
The unpublished document DE 10 2011 003 624 describes a method for reducing the data load of a vehicle-to-X communication channel in which a vehicle-to-X message is transmitted in at least a first and a second partial message over various communication channels. The first partial message contains here traffic-safety-relevant information, while the second partial message contains a security header and traffic-safety-relevant information which is partially identical to the first partial message. The portion of an overall message which is relevant for the data security is therefore transmitted exclusively via the second partial message, as a result of which the scope of the data of the first partial message remains low. The checking of the data security and reliability of the first partial message can then be carried out by means of the second partial message in that the traffic-safety-relevant information items respectively contained in the two messages are compared. If these information items correspond, traffic-safety-relevant information contained exclusively in the first partial message is also trusted. A computational intensive evaluation of a security header or decoding of the first message is therefore likewise not necessary.
Document DE 10 2011 006 305 which is unpublished discloses a method for reducing the computational load during data security checking of data packages which are received by means of vehicle-to-X communication. The data security checking is composed here of checking a signature which is encrypted by means of cryptographic algorithms and which is associated with high computational complexity and requires the use of dedicated electronics. In order to reduce the computational load, firstly pre-processing of the received vehicle-to-X message is performed, which pre-processing prioritizes said messages into different categories. The prioritization can be carried out here, using different criteria such as, for example, distance of the transmitter from the receiver or TTC (time to collision) of the transmitter with the receiver. Firstly, only the signatures of data packages provided with high priority are checked. If free computational capacity is still subsequently available, further data packages are checked. The possibilities are likewise described of verifying the content of a data package by means of surroundings sensor data, which makes checking of the signature superfluous.
However, all the vehicle-to-X communication methods known in the prior art have in common the fact that in so far as prioritization or other pre-sorting of the received information is performed or the transmitted information is split into a plurality of partial messages, this is performed only with an aim to reducing the computational work to be carried out in order to check the data security. On the contrary it is even known firstly to decode the useful data of a vehicle-to-X message and, under certain circumstances, dispense with data security checking depending on the information content of said message. In contrast, no significance is accorded to the computational work necessary to decode the useful data in the prior art even though the processors used at present for this purpose involve comparatively high manufacturing costs owing to their necessary computational capacity.
The object of the present invention is therefore to reduce the decoding computational complexity of a vehicle-to-X communication system with respect to the useful data portions of received vehicle-to-X messages.
This object is achieved according to the invention by means of the selection method for reducing the decoding computational complexity of a vehicle-to-X communication system and the vehicle-to-X communication system as described herein.